Drowning remains a significant cause of accidental deaths, especially among children. Many children are non-swimmers and die as a result of falling into pools or off of boats; however, many children and adults who are swimmers die either from panic, exhaustion, cramps, seizures or a combination thereof Children may drown despite being supervised while swimming. The parents or other adults supervising the child may have “just looked away for a second” only to find the child drowned on the bottom of the pool.
Several attempts have been made to address water safety with various degrees of success. For the non-swimmer, such as a toddler, the Safety Turtle™ device (Terrapin Communications Inc., Ottawa, Canada) is a bracelet, which when submerged triggers a pool-side alarm to activate and to notify that a person has fallen into the water. Although the Safety Turtle™ device is excellent at detecting a person falling into the water, it may not be suitable for a child who is allowed to play in the water because the Safety Turtle™ device will generally activate in the course of normal play whenever the child's arm is submerged and produce false alarms.
Monitoring systems that use wearable alarm devices can provide significant enhancements over pool alarms. For example, wearable swim monitors and drowning detection systems may track the swimmer in the water and identify possible drowning events. However, these systems may be limited in the sense that the swimmer or supervisor must proactively attach the wearable alarm device to the swimmer's body; if the device is not attached, the swimmer will not be protected.
Infrared cameras have been used as motion detectors such that if the infrared signal changes quickly, for example, when a person enters the field of view, an alarm or other motion-related event (e.g., turning on lights) is triggered. However, it may be difficult to determine with a traditional motion sensing infrared camera when the motion is around the pool or due to someone falling into the pool because traditionally analyzed motion detectors typically have difficulty distinguishing between a moving figure and a figure who has fallen into a pool. Infrared detectors have also been used to detect an emitted infrared signal around a perimeter of the pool; however, these systems are difficult to maintain since any misalignment may result in the infrared signal being directed away from the detector. Existing pool sensors may require complex algorithms and calibration steps to define the pool area for monitoring.